Nonskid paving surface construction



Patented Oct. 28, 1930 'umrsosrarss PATENT oFFics ERNEST A. YOUNG, OFSAN ANTONIO, TEIMS, ASSIGNOR T0 U VAIlLDE ROCK ASPHALT COMPANY, OF SANANTONIO, TEXAS, A CORPORATION OF 'IJFJLBLS NONSKID PAVING SURFACE CONSTRUC'IION Ho Drawing. Application filed July 28,

This invention relates to a new and improved paving construction andmore particularly to a. pavement which 18 provided with means forpreventing skidding and giv- 5 ing a firm traction surface.

In its specific form my invention relates to a pavement, the body ofwhich is formed of 29 crushing and grading it and then treating it witha flux such as an asphaltic oil or a paraffine base oil. in some methodsof preparation a the rock is heated, while by other methods the mixtureis made with the materials cold. In

- some cases a solvent such as kerosene-is also added to delay thesetting of the mixture, this being more generally used with the coldmixed material. Thisrock asphalt when so treated, is spread out on asuitable base and compact- 39 ed by means of a road roller or the like.When so treated a dense smooth surface is formed whichjis substantiallyimpervious to water and which is very wear-resisting under normal roadtrafic. Such a surface, however 5 at times becomes quite slippery whenwet or when an excess of the has is brought to the surface by heat. @nsteep slopes this surface does not ahord adequate traction under suchconditions. i I

It is an object of the present invention to provide a new and improvedpavement and method laying the same which aiiords an adequate tractioneifect under all conditions. it is a further object to provide such roadsurface base of which is roci: asphalt or the like, and which hecommerci lly produced by usual methods.

lt is an additional object to provide a construct-ion of this characterin which the trac- 59 tion effect is provided by means or appii 182?.Serial No. 209 17 9.

cation of crushed stone or the like harder than the rock asphalt base.

' Other and further objects will appear as the description proceeds.

According to the present invention rock asphalt may be made into asuitable road forming mix by any one of the methods well known in theart. When so treatedthe asphalt is laid upon the prepared base andspread in a substantially uniform layer or in such a layer .as to give asubstantially smooth surfacewhen compacted. it will be understoodthat'this rock asphalt mix when so laid is substantially balanced as tosize; that is, the larger-and smaller particles are so sized andproportioned as to provide a minimum of voids. After this material isspread a layer of crushed ,stone is scattered over the first layer orrock asphalt. This crushed stone is preferably considerably harderthanthe rock asphalt so that it tends to crush the asphalt wheir' forcedinto it by the compacting rolrer.

The crushed rock is also preferably not balanced as to size and in thepreferred construe tion the crushed rock is substantially a onesizedmaterial. A satisfactory size for the crushed rock has been tially thesize of the coarser rock asphalt aggregate in the rock asphalt layer.After the crushed rock has been scattered the entire mass is thoroughlycompacted by means of a road roller or the like.

Under some circumstances it may be found advisable to coat the crushedstone with fluid asphaltic material or with the same material which isused as a flux in forming the rock asphalt base. This coating enablesthe crushed rock to be more quickly consolidated into an integral masswith the rock asphalt, particularly if the rock asphalt min has littleexcess asphaltic' material.

it will be understood t at the specific de tails given are by way ofillustration only as various types of material may be used as a base anddifierent sizes and kinds of non-skid surface material may be used. 1contemplate such changes'and modifications as come within the spirit andscope of the appended claims.

found to be substan I claim:

1. The method of laying a pavement or the like which comprises spreadinga loose layer of crushed asphalt rock,'said rock being sized andproportioned to give a balanced mixture with a minimum of voids,spreading on said first layerascattered layer of crushed stone harderthan the first layer and compacting the layers together. i

. 2. The'method of laying a pavement or the like which comprisesspreadinga looselayer of crushed asphalt rock, said rock being sized andproportioned to give a balanced mixture with a minimum of voids,spreading on said first layer a scattered layer of crushed stone harderthan the first layer, said crushed stone bein a one-sized aggregatesubstantially the size of the coarser rock asphalt aggregate, andcompacting the layers together.

3; The method of laying a pavement or the like which comprises spreadinga loose layer of crushed asphalt rock, spreading on said first layer alayer of crushed stone harder than the first layer, said crushed stonehaving been coated with a relatively fluid asphaltic material, andcompacting the layers toget er.

4. The method of laying a pavement or the.

like which comprises spreading a loose layer of crushed asphalt rock,said rock being sized and proportioned to give a balanced mixture with aminimum of voids, spreading on said first layer a scattered layerofcrushed stone harder than the first layer, said crushed stone being aone-sized aggregate substantially the size of the coarser rock asphaltaggregate, and being coated with fluid asphaltic material and compactingthe layers together.

5. The method of laying a pavement or the like which comprises spreadinga loose layer of crushed rock asphalt mixed with a iiuz'z, spreading onsaid first layer a layer of crushed stone harder than the first layerandcompacting the layers together.

6. The method of laying a pavement or the like which comprises spreadingloose lay of crushed rocir asphalt mixed a r spreading on said firstlayer layer crushed. stone harder than the first layer and compactingthe layers together, crushed stone having been treated with the same asrock asphalt.

7. The method ofslaying a pavement or the like which comprises spreadingloose layer of crushed rock asphalt mixed with a said rock being sizedand proportioned togive a balanced mixture with a minimzini of voids,

spreading on said first layer a layer at crushed stone harder than thefirst layer compacting the layers together.

8. A non-skid pavement construction comprising a compacted body crushedrock asphalt balanced as to size and with a minimum of voids andscattered crushed rockharder than the asphalt reel: embedded in theupper surface of the body.

of July, 1927.

91A non-skid pavement constructioncomprising a com acted body of crushedrock asphalt and a ux and scattered crushed rock harder than the asphaltrock embedded in the upper surface of the body and adhering to the rockasphalt body by means of the flux and the asphalt. Signed at SanAntonio, Texas, this 2nd day ERNEST YOUNG.

